1. Field of the Invention
The present invention relates to methods and apparatus for concentrating minerals by the flotation separation and classification procedure.
2. Description of the Prior Art
In the natural state, certain minerals, such as phosphates, coal and sylvite, are often found admixed with heavier aggregate materials, such as rocks, clay and the like. After mining the mineral in bulk, it is therefore frequently necessary to separate the desired minerals from the undesirable materials.
The process of flotation separation and classification is well known in the prior art for these purposes. Briefly, this process contemplates the mixing of the bulk product in a water slurry with known emulsifiers and surfactants. Air (or another suitable gas) is then bubbled through the slurry and the lighter, desired minerals float to the top with the bubbles, while the undesirable materials (referred to as "tailings") sink to the bottom of the container. A discussion of the flotation separation process is contained in U.S. Pat. No. 2,931,502 to Schoeld, et al. Equipment manufactured by Heyl and Patterson, Inc. of 55 Ft. Pitt Boulevard, Pittsburgh, Pa. under the trademark "CYCLO CELLS" utilizes the flotation separation process.
One of the disadvantages of most flotation separation processes is that frequently large masses of the desired mineral, particularly coarse particles, are not carried to the top of the vessel during the aeration step, and sink to the bottom of the vessel with the "tailings". This results in a low efficiency of recovery of the desired mineral.